I. Field of the Invention
The present invention relates generally to conveyor systems and, more particularly to a conveyor system with a turn table for transferring pallets from a first conveyor line to a second conveyor line.
II. Description of the Prior Art
Many assembly lines, for example assembly lines of the type used in automotive industries, utilize conveyor lines for transferring the part being assembled from one work station to the next. Furthermore, many of these previously known conveyor lines include a plurality of power and free rollers which are spaced apart from each other and define a conveyor line. Pallets carrying the part being assembled are then supported and propelled by the power and free rollers.
Typically, the conveyor line for these previously known conveyor systems comprise a pair of spaced apart and elongated rails having the power and free rollers rotatably mounted between the rails. A work piece carrying pallets then have a lower surface which sits upon the power and free rollers.
It would be desirable for such conveyor systems to have a single elongated conveyor line with the assembly of the part beginning at one end of the line and the finished product exiting off the opposite end of the line. However, in most cases such a conveyor line is impractical due to factory floor space limitations. Instead, as a practical matter, the assembly line is divided into a number of shorter sections with the pallet being transferred from one conveyor section to the next conveyor section as the assembly of the part progresses.
In order to transfer the part from one conveyor section to the next conveyor section, it has been the previously known practice to utilize transfer or cross conveyor sections between the end of one conveyor section and the next adjacent conveyor section which typically is spaced from but parallel to the first line. This practice, however, has disadvantages for a number of reasons.
One disadvantage of these previously known systems is that the transverse conveyor lines for transferring the pallet from one conveyor line to the next sequential conveyor line must, of course, be of a length sufficient to accommodate the pallet. Consequently, a space is created between the two sequential conveyor lines equal to the length of the transverse conveyor lines and the space is essentially wasted. Factory floor space, of course, is not only limited but also expensive.
The lateral space in between the sequential and adjacent conveyor lines employed by these previously known systems is also disadvantageous since it necessarily requires that each conveyor line be supplied with its own power supply system, pressurized air and the like. This increases the overall cost of the conveyor system.
A still further disadvantage of these previously known conveyor systems is that the parts have traditionally been supported on top of the pallets and, thus, on top of the conveyor line. Such a pallet construction often times requires awkward and elevated hand movements for the worker. Such awkward and elevated hand movements for the worker results in worker fatigue and poorly assembled parts.